#include<stdio.h>

double fact(int n)
{
	int sign;
	double prod=1;
	if(n>=2)
	{
		for(sign=2;sign<=n;sign++)
		{
			prod*=sign;
		}
	}
	return prod;
}

int main()
{
	double result=0;
	int m,n;
	scanf("%d %d",&m,&n);
	result=1.0*fact(n)/(fact(m)*fact(n-m));
	printf("result = %.0lf",result);
	return 0;
}
